title: Variable alteration of regional tissue oxygen pressure in rat hippocampus by acute swimming exercise.
abstract: One of the events in the brain is an increasing cerebral blood flow during exercise. The tissue oxygen level may be increased because blood flow correlates with tissue oxygen level. However, it is little known whether the tissue oxygen pressure in hippocampal region (Hip-pO2) will be affected by exercise.
  
  
  OBJECTIVE
  The aim of this study is to examine Hip-pO2 levels in the hippocampus and its changes during exercise.
  
  
  METHODS
  We applied improved Clark-type electrodes to measure Hip-pO2 level in the hippocampus of rats that were subjected to three groups, 2h swimming without weights (low intensity, n=6), 2h swimming with a 5 g weight (moderate intensity, n=6), and 2h swimming with a 10 g weight (high intensity, n=6).
  
  
  RESULTS
  Exercise affected the Hip-pO2 level, the responses varied with the exercise intensity and duration. Interestingly during and after the Low intensity swimming the Hip-pO2 level showed long lasting enhancement (10-20% above resting level). But the moderate and high intensity swimming increased Hip-pO2 level at the start of the swimming (50%, P<0.05 and slightly above resting level, respectively, at 10 min of 2h swimming) and then began to decrease (at 120 min and 10 min of 2h swimming, respectively), and suppressed the Hip-pO2 levels during post exercise resting period (2h) (85-95% of resting level, NS and 60-70% of resting level P<0.05, respectively).
  
  
  CONCLUSIONS
  We propose that exercise-induced hippocampal hyper/hypo oxygen condition may participate in beneficial exercise effects on brain function.
authors.affiliation: Department of Materials Sciences and Engineering, Nagoya Institute of Technology, Gokiso-cyo, Showa-ku, Nagoya 466-8555, Japan.
authors.lastname: Gegentonglaga
authors.forename: H
authors.initials: H
authors.lastname: Yoshizato
authors.forename: Y
authors.initials: Y
authors.lastname: Higuchi
authors.forename: Y
authors.initials: Y
authors.lastname: Toyota
authors.forename: Y
authors.initials: Y
authors.lastname: Hanai
authors.forename: Y
authors.initials: Y
authors.lastname: Ando
authors.forename: A
authors.initials: A
authors.lastname: Yoshimura
mesh_terms: D000818:Animals; D006624:Hippocampus / Q000378:metabolism*; D008297:Male; D010100:Oxygen / Q000378:metabolism*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011312:Pressure; D051381:Rats; D012146:Rest / Q000502:physiology; D013550:Swimming / Q000502:physiology; D013997:Time Factors
chemical_list: D010100:Oxygen
keywords: Exercise; Exercise intensity; Hip-pO(2); Hippocampus; Oxygen pressure (pO(2)); VO(2)max; h; hour; maximal oxygen uptake; pO(2); the tissue oxygen pressure; the tissue oxygen pressure in hippocampal region